/**
* Problem 8 - Largest product in a series
* @see {@link https://projecteuler.net/problem=8}
*
* The four adjacent digits in the 1000-digit number that
* have the greatest product are 9 × 9 × 8 × 9 = 5832.
* Find the thirteen adjacent digits in the 1000-digit number
* that have the greatest product. What is the value of this product?
*
* @author ddaniel27
 */
package problem8

const number = "7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450"

func Problem8(window int) uint {
	max := uint(0)

	for i := 0; i < len(number)-window; i++ {
		product := uint(1)

		for j := 0; j < window; j++ {
			n := uint(number[i+j] - '0')
			product *= n
		}

		if product > max {
			max = product
		}
	}

	return max
}
